Solar beating for emergency diesel generators

Emergency diesel generators use large amounts of electric resistance heat to keep the engines warm and ready to start, all year. The annual electric use for mid sized generators (150 KW-1,000 KW) in outdoor enclosures can be 10,000 to 30,000 kwhr in mild climates with 4,000 heating degree days (65 F base). With over 600,000 emergency diesel generators installed in the US, standby electric heating consumes an estimated 6 billion kilowatt hours and $360 million per year. The electricity is consumed to heat the jacket water of the engine by means of an electric resistance cartridge heater. The heaters deliver 130 degree F water to the engine. An alternative to electric heating of the jacket water, is to solar heat the air in the enclosure up to 110 F. This reduces the heat loss from the engine and therefore reduces the electricity consumption of the electric resistance heater. The paper describes the opportunity to solar heat emergency generators. The design and construction of three systems for the US Geological Survey in Reston, VA is described.